The retreading of pneumatic tires is a common practice, as it allows the original casing (or carcass) of a tire to be reused once the tread has served its useful life. A conventional retreading process comprises extruding a body of uncured rubber (“camel-back”) onto a previously used tire carcass. The extruded body of rubber consists of a base composition and a cap composition selected to match retread requirements. The “camel-backed” casing is then inserted into an enclosed heated mold and cured. The tread pattern is impressed on the blank in the mold and is bonded to the casing by the application of heat and pressure.